Janus Mikani and Celeste Ritsuko work all hours in the Criminal Investigation Division, keeping citizens safe. He’s a charming rogue with an uncanny sixth sense; she’s all logic—and the division’s first female inspector. Between his instincts and her brains, they collar more criminals than any other partnership in the CID.

Then they’re assigned a potentially volatile case in which one misstep could end their careers. At first, the search for a missing heiress seems straightforward, but when the girl is found murdered—her body charred to cinders—Mikani and Ritsuko’s modus operandi is challenged as never before. It soon becomes clear the bogeyman has stepped out of nightmares to stalk gaslit streets, and it’s up to them to hunt him down. There’s a madman on the loose, weaving blood and magic in an intricate, lethal ritual that could mean the end of everything…

I'm intrigued by this title for a couple of reasons: first, A.A. Aguirre is a pseudonym for the husband and wife team of Ann and Andres Aguirre-- and after loving the books written by the husband/wife team of Ilona Andrews, I'm all set to expect good things from this pairing (especially since Ann Aguirre already has a track record as a pretty good writer); secondly, Steampunk! (I know it's everywhere these days, but I still love it).